Polygons are used in
computer graphics
Computer graphics deals with generating images and art with the aid of computers. Computer graphics is a core technology in digital photography, film, video games, digital art, cell phone and computer displays, and many specialized applications. ...
to compose images that are
three-dimensional
In geometry, a three-dimensional space (3D space, 3-space or, rarely, tri-dimensional space) is a mathematical space in which three values (''coordinates'') are required to determine the position (geometry), position of a point (geometry), poi ...
in appearance, and are one of the most popular geometric building blocks in computer graphics.
Polygons are built up of
vertices, and are typically used as triangles.
A
model
A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , .
Models can be divided in ...
's polygons can be rendered and seen simply in a
wire frame model
In 3D computer graphics, a wire-frame model (also spelled wireframe model) is a visual representation of a three-dimensional (3D) physical object. It is based on a polygon mesh or a volumetric mesh, created by specifying each edge of the p ...
, where the outlines of the polygons are seen, as opposed to having them be shaded. This is the reason for a polygon stage in
computer animation
Computer animation is the process used for digitally generating Film, moving images. The more general term computer-generated imagery (CGI) encompasses both still images and moving images, while computer animation refers to moving images. Virtu ...
. The ''polygon count'' refers to the number of polygons being rendered per
frame
A frame is often a structural system that supports other components of a physical construction and/or steel frame that limits the construction's extent.
Frame and FRAME may also refer to:
Physical objects
In building construction
*Framing (con ...
.
Beginning with the
fifth generation of video game consoles
The fifth generation era (also known as the 32-bit era, the 64-bit era, or the 3D era) refers to computer and video games, video game consoles, and handheld gaming consoles dating from approximately October 4, 1993, to March 23, 2006. The best ...
, the use of polygons became more common, and with each succeeding generation, polygonal models became increasingly complex.
Competing methods for rendering polygons that avoid seams
*
Point
**
Floating Point
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a signed sequence of a fixed number of digits in some base) multiplied by an integer power of that base.
Numbers of this form ...
**
Fixed-Point
**
Polygon
In geometry, a polygon () is a plane figure made up of line segments connected to form a closed polygonal chain.
The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon ...
**because of
rounding
Rounding or rounding off is the process of adjusting a number to an approximate, more convenient value, often with a shorter or simpler representation. For example, replacing $ with $, the fraction 312/937 with 1/3, or the expression √2 with ...
, every
scanline
A scan line (also scanline) is one line, or row, in a raster scanning pattern, such as a line of video on a cathode-ray tube (CRT) display of a television set or computer monitor.
On CRT screens the horizontal scan lines are visually discernib ...
has its own direction in space and may show its front or back side to the viewer.
*
Fraction (mathematics)
A fraction (from , "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, thre ...
**
Bresenham's line algorithm
Bresenham's line algorithm is a line drawing algorithm that determines the points of an ''n''-dimensional raster that should be selected in order to form a close approximation to a straight line between two points. It is commonly used to draw li ...
**Polygons have to be split into
triangle
A triangle is a polygon with three corners and three sides, one of the basic shapes in geometry. The corners, also called ''vertices'', are zero-dimensional points while the sides connecting them, also called ''edges'', are one-dimension ...
s
**The whole triangle shows the same side to the viewer
**The
point numbers from the
Transform and lighting
Transform, clipping, and lighting (T&L or TCL) is a term used in computer graphics.
Overview
Transformation is the task of producing a two-dimensional view of a 3D computer graphics, three-dimensional scene. Clipping (computer graphics), Clipp ...
stage have to converted to
Fraction (mathematics)
A fraction (from , "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, thre ...
*
Barycentric coordinates (mathematics)
In geometry, a barycentric coordinate system is a coordinate system in which the location of a point is specified by reference to a simplex (a triangle for points in a plane, a tetrahedron for points in three-dimensional space, etc.). The ba ...
**Used in
raytracing
See also
*
Low poly
Low poly is a polygon mesh in 3D computer graphics that has a relatively small number of polygons. Low poly meshes occur in real-time applications (e.g. games) as contrast with high poly meshes in animated movies and special effects of the s ...
*
Polygon
In geometry, a polygon () is a plane figure made up of line segments connected to form a closed polygonal chain.
The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon ...
, for general polygon information
*
Polygon mesh
In 3D computer graphics and solid modeling, a polygon mesh is a collection of , s and s that defines the shape of a polyhedron, polyhedral object's surface. It simplifies Rendering (computer graphics), rendering, as in a wire-frame model. The fac ...
, for polygon object representation
*
Polygon modeling
In 3D computer graphics, polygonal modeling is an approach for modeling objects by representing or approximating their surfaces using polygon meshes. Polygonal modeling is well suited to scanline rendering and is therefore the method of choice for ...
References
{{DEFAULTSORT:Polygon (Computer Graphics)
3D computer graphics